Question

I have the following code below that is meant to change a class var called “today” forward or backward by one day. It will work one time but then after that it crashes. It will do the same no matter if I press the left button or right button. What am I doing wrong?

the var today is a class var initiated as .. today = [NSDate date]

Here is the method that crashes:

(IBAction)changeDateByOne:(id)sender{

    NSDate *newDay;
    NSDate *currentDay = today;

    NSTimeInterval secondsPerDay = 24 * 60 * 60;

    if(sender == leftButton){
         newDay = [currentDay addTimeInterval:-secondsPerDay];

    }else if(sender == rightButton) { 
         newDay = [currentDay addTimeInterval: secondsPerDay];
    }

    today = newDay;
}

Answer 1

Not only do you need to retain the date created, but you also need to release the existing value held by “today,” otherwise you’ll leak the old reference.

When initializing the instance, use:

today = [[NSDate date] retain];

I would change the last line to:

[today release];
today = [newDay retain];

And finally, in your dealloc method, add:

[today release];

before calling [super dealloc];